Oil is typically supplied to a bearing damper to reduce the oscillation amplitude of an unbalanced engine rotor (e.g. bowed rotor during engine start). As the unbalanced engine rotor rotates, an oil pressure oscillation may be induced in the bearing damper oil supply line. A check valve in the bearing damper oil supply line may be provided to prevent the large amplitude oil pressure oscillation from working its way upstream of the check valve. However, depending upon the design and dynamic response of the check valve, a large amplitude oil pressure oscillation may still work its way upstream of the check valve.